Well, what I did was just remove the headrest and brought it in the house. I didn't see a need to 'mod' it since the child seat is there anyway and the child seat is staying there. And after the child seat is removed it's just going to have a booster seat put in its place anyway. When my son is old enough for riding without a child seat/booster seat (many yrs away so I doubt I'll still have the Jeep anyway), or sell/trade, I can just put the headrest back. Looks like the mod would be great for those who install/remove their child seats but like I said, mine stays put. Thanks to everyone for their help with this.

With a Britax Marathoner in a Commander, you can recline the seat all the way, and it fits well. I had to work with the seat/recline combo to make it work well, but I was able to do it without removing the headrest.

jcoxhome,
Are there two steel rods sticking up from the rear seat ? Like right behind your child seat ? Yea.. I wasnt getting a warm fuzzy feeling about that.

Yep, sure are. I have the Britax Boulevard child seat and it's pretty tall so the 2 steel posts stick up above the back of the child seat about 3 inches. They are well above my son's head (about 1 foot) since the seat is so tall (it's so tall actually that I don't think the mod would even be enough room for me). I was actually thinking of what I could place over them. I was thinking maybe some finger puppets

There is an excellent car seat message board on iVillage that is "manned" by lots of car seat techs. I'm sure they would have ideas for you and a way to have a tech check your install to be sure it's safe. I'm glad you're looking into this! I would have had this problem too if my youngest wasn't in a booster seat now!